Dc to DC charger for lithium Battery.

HandyWalter · Senior Member

Dc to DC charger for lithium Battery.

Peter_n_Margaret · Guru

HandyWalter wrote:
I have a Diverse system power board in my caravan. It does not have a lithium set up.

What exactly is the "lithium set up" that you think you need.

They are just batteries with some particular charging requirements like any other batteries.

Cheers,

Peter

Mike Harding · Guru

May I suggest that until you understand a great deal more about electricity or have quality professional support you do not cut any wires at all.

Whenarewethere · Guru

Mike Harding wrote:
May I suggest that until you understand a great deal more about electricity or have quality professional support you do not cut any wires at all.

Agree.

HandyWalter · Senior Member

I do understand 12V very well. I just thought someone would know if you can have power flow both ways through the charger. I have an old Redarc DC to DC,which does, but just wondering if anybody has got a new one (with lithium Algorithims) and could tell me. If not I will ask in other places.

HandyWalter · Senior Member

Peter_n_Margaret wrote:
What exactly is the "lithium set up" that you think you need.
They are just batteries with some particular charging requirements like any other batteries.
Cheers,
Peter

Peter, I want to replace the AGM with Lithium. Yes i know lots of Lithium manufacturers say you dont need a special charger with lithium algorithims but I would rather fit one then I know the battery will be fully and properly charged, with no damage. Easiest way without changing the power board would be to get the DC power coming out of the power board to go to the DC to DC lithium charger and then onto the battery. Ie simple cut the wire there now and put the charger in (ie in line). However, as I dont have a DC to Dc charger with Lithium and my old Dc to Dc charger does allow flow both ways, I was asking if anybody here who had a a DC to Dc charger with lithium algorithims could tell me if current can flow both ways. Then I can determine what is the best way to wire everything up. i thought I explained it but perhaps not so well.

Whenarewethere · Guru

I have 2 Victron 9amp DC-DC chargers, you can put as many as you like in parallel.

They are dumb chargers, I have set the voltage output to the voltage I want, ie a compromise! It would be better to have a smart DC-DC charger so it has a good charging profile for which ever battery one has.

The other option I am thinking of, is to buy a 12v to 24v DC-DC charger & feeding it into my Victron MPPT solar controller, which has an excellent charging profile for all batteries.

Peter_n_Margaret · Guru

Lithium batteries are not something magic. Check what charging parameters are appropriate for yours (most will accept a wide range) and then check your existing sources. There is a very good chance that what you have will be perfectly OK, but you will never know until you find out both what you have and what you need, neither of which you have shared and that could suggest that you don't know?
Cheers,
Peter

HandyWalter · Senior Member

Sorry I asked the question. Clearly people here cannot read or do not understand what I am asking. Therefore I will stop asking on this. As none of you can answer my question clearly you are all ignorant of DC to DC chargers with a lithium profile, just like me. Its not rocket science what I am asking. Either you know the answer or you dont! And clearly so far know one who has responded does know. Thanks anyway!!

-- Edited by HandyWalter on Tuesday 20th of October 2020 05:07:56 PM

Whenarewethere · Guru

HandyWalter wrote:
I have a Diverse system power board in my caravan. It does not have a lithium set up.

You clearly state NOT asking about lithium.

0.5mV 'flow of power the other way' with 2 Victron DC-DC chargers in parallel & 4 x 26AH gel batteries at 12.7v stuck on the other end. Measured with a Kyoritso 2046R cat4 meter.

iana · Guru

Intervolt have a DC-DC charger for lithium, made in WA.

Warren-Pat_01 · Guru

Hi Walter,
I googled your Diverse Power Board & came up with a New Age Owners Group, Forum. I'd suggest if you're not happy with this forum's answers that you go there.

Some of us might be wizards, some not so. Most of us are retirees enjoying life as it comes, sorting out our problems as they appear. The advantage of a forum is that "perhaps someone might have had a similar issue and can help. I can only assume your van came with manuals. Some manufacturers give only the basic amount of info, some might be more helpful.

At one of my past work places, we went to specialisation - there was a saying there - "That we get to know more about less and less, so eventually we know everything about nothing!"

Getting back to your statements - it is current flow that you get when a battery (of some voltage) is coupled to a load (your power circuits). And yes a diode will either pass or block current depending on the cct diagram.
If you don't know much about your system, ask someone who is more familiar with it.

travelyounger · Guru

HandyWalter wrote:
I have a Diverse system power board in my caravan. It does not have a lithium set up. Looking at the wiring diagram, the battery currently has one positive wire to the unit. I presume this wire both powers all the fused appliances and is also the main wire to charge the battery when the van is connected to 240V (reduced to 12V). I was thinking of just cutting that wire and putting a DC to DC charger in between this wire from the power board and the battery. However I am just wondering about power flow (is that what you call it??) Ie the dc to dc charger would get 12V from say the 240 charger. But would the flow of power go the other way and provide power to the fuses? Ie is there a diode in the DC to Dc charger that only allows current to flow into the unit and to the battery but not the other way? Yes I know I could replace the Diverse system with a new BMPO system but the space in my cupboard is not big enough.

I have an enerdrive system set up for agm but can be changed to lithium charging.

I contacted enerdrive and they told me everything I needed to know about setting it up maybe you should contact the the company that makes your charger and then you might get the information you are after.

Cheeks

HandyWalter · Senior Member

I give up. I will seek answers elsewhere. Thanks.

Magnarc · Guru

Walter,

Whilst I sympathise with your frustration surely your best course of action is your local Auto Elec?????? Has to be one in Greensborough who could help you.

Mike Harding · Guru

Magnarc wrote:
Walter,
Whilst I sympathise with your frustration

I don't.

If people want correct answers to complex technical questions then:

1 - they must ensure it is a question their audience is likely to have an answer to.

2 - they must craft the question in such a way as to be clear and present as much uncluttered information as possible.

3 - they should ensure they have the knowledge to understand what may be a complex reply.

We have another similar question currently: "I switched something off in my motorhome and when I switch it back on it makes a noise, what is it?"

I don't know, do I? It could be a trapped mouse being electrocuted!

Whilst these forums have a wealth of knowledge and people who spend much time researching and answering questions none of us are mind-readers. And if someone is seeking free knowledge (don't try this on a lawyer's forum) they should at least do us the courtesy of taking the time and trouble to frame the question.

Warren-Pat_01 · Guru

Hi Mike, others who have answered positively,
Perhaps we should ask Cindy to produce a "Sticky" note suggesting that most of us can only offer basic cures, based on some experience.
For people wanting to know more details than their manuals state, they should be prepared to pay for the info from another source, e.g. caravan repair shop, auto-electrician.

We have lost some good members with backgrounds in these increasingly complex power systems in recent years, perhaps getting frustrated by questions posed by "keyboard warriors" who expected everything for nothing, perhaps getting upset if the answer didn't meet their criteria.

Heaven forbid if some inexperienced person should "plate himself" while working on their power systems.

It would also prevent those of us who like to keep our fingers, brains interested in our caravans with authorities clamping down further on "back yarders".

pinballpat · Veteran Member

Hi Handy if i am not wrong ..i believe you are asking if your battery bank will feed power back into your DC to Dc charger ??? and weather you need a diode to block any power feedback ? is this correct??

Also Mike Harding i think i need your help with this to extract///relevant details from Handy ...i ask you Mike as i consider you 1 of the few "Grounded" people on this forum who does not rip the head off a newcomer...everyone was a newcomer at some stage even the members that date back to the Triassic, Jurassic and Cretaceous Era.....

-- Edited by pinballpat on Friday 23rd of October 2020 08:37:10 AM

-- Edited by pinballpat on Friday 23rd of October 2020 08:44:55 AM

Whenarewethere · Guru

On a few other forums it is surprising the number of people who simply can't be bothered to look up the manual for information.

Additionally there is often a full service manual with wiring diagrams on these websites for their cars etc.

I have downloaded the full service manual for my car. It is not the exact model but it is close enough to solve most problems.

Get the information for your car, caravan, boat etc so you are armed!

Mike Harding · Guru

pinballpat wrote:
Also Mike Harding i think i need your help with this to extract///relevant details from Handy ...i ask you Mike as i consider you 1 of the few "Grounded" people on this forum who does not rip the head off a newcomer...everyone was a newcomer at some stage even the members that date back to the Triassic, Jurassic and Cretaceous Era.....

Sadly... I am not perfect and sometimes become frustrated with people (well... quite often actually).

It is not my desire to drive people away or make them feel uncomfortable and I do not criticise ignorance for I possess far more ignorance than knowledge and ignorance is no sin but if we wish to learn we must prepare ourselves and be receptive to our teachers - it is no good going to school without a pencil and paper or without having read the books you were instructed to and the like....

Sometimes my temper is shorter that it ought to be and for that I apologise.